Apparently, everyone expected crime to rise because of the weak economy, which I find strange, because there is zero evidence of any relationship between violent crime and the economy, and a relatively weak one between property crime and the economy. Plus, relative to 2009, the economy in 2010 was substantially improved.

We spent an entire chapter in Freakonomics exploring the factors that do and do not seem to have brought down the rate of violent crime in the U.S. In short, factors that matter include: number of police; number of prisoners; changes in drug markets; and the availability of abortion. And those that don’t seem to much matter: the economy; innovative policing strategies; most gun laws; capital punishment; and demographics.

There is of course no reason for anyone to have complete confidence in the arguments we presented, even if they were more empirical than most arguments about crime. Still, as Levitt said in the excerpt above, it is surprising that so many people seem wedded to the view that the economy drives violent crime even when the evidence supports the contrary.

So, given the amount of bafflement on the issue, it seemed like a good time to convene a Freakonomics Quorum. We put out the following question to a group of experts including some of the very academics whose work we challenged in Freakonomics, as well as former New York and Los Angeles police chief William Bratton:

Violent crime has continued to fall, even during a sharp economic downturn. Tell us what you think — or even better, what you know — about the factors that do and don’t affect crime.

Here are their replies. In the interest of fairness, I will keep my thoughts to myself and let you judge whose arguments are most persuasive. Thanks to all for participating. It’s a fascinating quorum.

Alfred Blumsteinis a professor of urban systems and operations research and the former dean of the H. John Heinz III College of Public Policy and Management at Carnegie Mellon. He is a fellow of the American Society of Criminology, and served on the President’s Commission on Law Enforcement and Administration of Justice. In 2007, he was awarded the Stockholm Prize in Criminology.

I was among the criminologists recently contacted by the New York Times to provide a clear explanation for the recent FBI statistics indicating a continued decline in violent crime rates in 2010. The uncertain responses provided to the Times led to the front-page headline “Steady Decline in Major Crime Baffles Experts.” Our hesitancy was undoubtedly a result of a reluctance to report what could not be more than speculation rather than a documented effect. One follow-up to that article was a flurry of e-mails documenting the sender’s favorite causes, ranging from guns to transcendental meditation to lead content in water. This highlights the array of potential explanations and the difficulty of demonstrating the influence of any particular one. And most of the explanations I’ve heard represent continuing change rather than the challenging aspects of the discontinuity from a steady crime rate to a sudden sharp decline.

When I first learned about the crime declines of 2009, I was surprised. It followed a period of impressive flatness in violent crime trends since 2000, with year-to-year shifts on the order of 1 or 2%. That flat trend followed a dramatic decline of over 40% in homicide and robbery between 1993 and 2000. During the flat period, individual cities fluctuated, but the national rates were impressively constant. That made the large drop in 2009 particularly impressive, both for its magnitude and its direction.

That obviously got us all thinking about what happened in 2009 aside from the recession. The one striking event that comes to mind is the inauguration of our first African-American president, a particularly salient event in this context because blacks are disproportionately involved in arrests for robbery and homicide. Could it be possible that an “Obama Effect” is influencing some portion of this high-risk group characterized by joblessness, lack of education, and involvement in inner-city gangs?

I was encouraged in this view when I later had access to 2009 arrest data, which provide some interesting observations:

For murder, arrests of blacks decreased 2.7% and arrests of whites increased 0.4%

For robbery, arrests of blacks decreased 2.1% and arrests of whites increased 2.1%

For drug use offenses, which are often associated with violence, arrest of blacks decreased 3.3% and arrests of whites increased 2.0%

I also looked at 23 high-crime cities that accounted for 28% of the murders and 32% of the robberies. Of the 23 cities, murder went down in 19 and up in only four, while 13 cities dropped by more than 10%, including four that dropped by more than 20%. Similarly, robbery decreased in 21 cities and increased in only 2, with 9 cities dropping more than 10% including 3 that dropped more than 20%.

These results certainly can’t be said to prove an Obama Effect, but they’re certainly not inconsistent with one. On the other hand, I looked at the trends in a number of individual cities and found them not to be consistent with expectations of an Obama Effect. There are obviously many problems with arrest statistics. The jurisdictions that report their race-specific arrest data to the UCR represent only about 75% of the U.S. population. An arrest always involves some discretion, but probably less so for murder and robbery than for minor offenses like disorderly conduct. The arrest statistics are aggregated for the nation but it is interesting to note that murder decreased by more than 20% in three of the four cities that I studied (Atlanta, Birmingham, and Washington D.C.), where blacks comprise over 60% of the population. In contrast, the fourth city was Phoenix, which has a very small African-American population, highlighting the fact that crime rates are always driven by many complex factors, and almost always defy attempts to link trends to a single factor.

The results of these preliminary inquiries are interesting enough that they should be pursued further. It will be several months before we see the 2010 arrest statistics that contain demographic information. If there is an Obama Effect, it should show itself not only in crime statistics, but in other domains such as school dropout rates. If we find that effect, it would represent the best news yet of movement in the many distressing racial disparities that continue to plague the nation.

William J. Bratton is the only person to have ever led the two largest police forces in the U.S., NYPD and LAPD. He is currently vice chair of the Homeland Security Advisory Council, and chairman of Kroll, a leading risk-consulting firm.

There is no immediate causal relationship between poverty or economic downturns and crime. An increase in employment or a decline in GDP usually will not lead to a commensurate increase in criminal activity. This is because most poor people are not criminals and never will be, even if their circumstances grow markedly worse. They are more likely to take the pressures of bad times out on themselves and their families: suicide rates and domestic violence rates often rise faster in downturns than property crime and violent crime against strangers.

This statement comes with a major proviso, however. Extended and severe downturns that engender long-term unemployment rates of 15 or 20 percent in poor and minority communities can have criminogenic effects, not only because they foreclose economic opportunities, but also because they perpetuate an underclass culture that fails to educate and socialize young men. As these young men grow, they become the foot soldiers for crime of all kinds, including drug dealing, robberies, burglaries, auto theft, and other larcenies, as well as targeted and random shootings in the public square.

Such extended downturns are also likely to cause revenue shortfalls at the state and local levels that may result in sharp cuts to policing and other government services, as is already happening now. These cuts tend to reduce dramatically the staffing flexibility of police managers and the very innovative policing programs that have helped drive the crime decline of the past 20 years because the resources that remain are needed for baseline operations. If the police are disabled in this way just as a larger pool of crime-prone youth comes on the scene, you might see a repeat nationwide of the circumstances that drove crime in New York City in the late 1970s and 1980s. Disabled significantly by the New York City fiscal crisis and subsequent layoffs of police personnel, the NYPD failed to contend with the emerging crack epidemic of the early 1980s, and violent crime surged. With these dual factors – poorly socialized youth and weakened police departments – simultaneously at work, the long-term outlook for crime could worsen significantly, and the positive crime trends of the past 20 years could be reversed.

Based on the research presented in my book, New York Murder Mystery, I have come to the conclusion that crime rates do not rise and fall in lock-step with poverty rates and unemployment. Such a strong correlation and such an obvious direct relationship has never been claimed by criminologists. Many other factors play a part in shaping behavior. It takes years, maybe decades, for a person or family or peer group to become ground-down and mired in anger, resentment, and despair. However, for centuries, neighborhoods burdened by poverty, chronic unemployment, and limited legitimate opportunities have been the breeding grounds of violence and theft. Street crime is an expression of alienation and rage, and functions as a distorted form of protest. But invariably, these illegal actions turn out to be inappropriate, misguided, misdirected, and ultimately counterproductive for the individuals involved and for the disadvantaged community.

Since the financial meltdown, poor and working people have been taking a terrific political and economic beating — but they are hardly visibly complaining, organizing, mobilizing or fighting back. If and when they do react to the deteriorating conditions in their personal lives and neighborhoods, a surge in street crime or political protest movements — or both — will materialize.

Gary LaFreeis a professor of criminology and criminal justice at the University of Maryland, where he is also director of the National Consortium for the Study of Terrorism and Responses to Terrorism (START). He is a past president of the American Society of Criminology, and served four years as chair of New Mexico’s Crime and Juvenile Justice Coordinating Council.

Imagine two types of crime explanations: ahistorical and historical. Ahistorical explanations could be biological, psychological or social. They assume that if poverty, for example, causes crime in contemporary America, it similarly caused crime in Ming, China or ancient Rome. By contrast, historical explanations are one-time events. There may be similarities between an economic crisis in contemporary America and 16th century Venice, but the two are nonetheless historically unique. In general, researchers and policy makers have downplayed historical explanations for crime. I’ll give three examples of historical events in recent American history that likely had a big impact on crime rates.

First, driven especially by the Civil Rights Movement and displeasure with the War in Vietnam, America entered an “age of protest” during the 1960s and much of the 1970s, where virtually every social institution was called into question. In my book, Losing Legitimacy: Street Crime and the Decline of Social Institutions in America, I argue that this legitimacy crisis was in large part behind the rapid increase in violent crime rates during this period. Second, the discovery and rapid distribution of crack cocaine in the mid-1980s had a startling short-term effect on violent crime rates. In a recent article in the American Sociological Review, my colleagues and I found that a proxy measure of crack cocaine had a greater impact on big city crime than more common measures like unemployment.

The crime bust we are now experiencing can be seen in part as a consequence of the end of both of these earlier historical phenomena— there is currently no social movement in the U.S. with the power to fill the streets with violent protesters, and no new drug with the destructive-addictive appeal of crack. And we are still in the aftermath of another historical event that likely increased the legitimacy of American institutions and dampened crime — the attacks of 9/11.

James Alan Foxis the Lipman Family Professor of Criminology, Law, and Public Policy at Northeastern University in Boston. He also writes the “Crime and Punishment” blog for the Boston Globe.

According to the New York Times, we criminologists are clueless when it comes to explaining the drop in serious crime. To the contrary, a range of plausible explanations have been advanced to account for the downturn in lawlessness that this nation has enjoyed since the early 1990s. Over the long-term, the welcomed trend can be linked to several factors: the calmer aftermath of the late-1980s crack epidemic that caused city crime levels to spike; improved police strategies that rely heavily on innovative technology and sophisticated crime analysis tools; expanded use of incarceration along with longer sentences that have kept more criminals off the streets; and the graying of America whereby the fastest growing segment of the population are the aging “baby-boomers” who are now all over 50.

Reading beyond the headline of the Times story however, what “baffled” me and other criminologists was the short-term plunge in crime from the first half of 2009 to the first half of 2010, especially the 6.2% drop in violent crime that included a 7.1% dip in murder. There is nothing even close to definitive that can account for such a large reduction over such a limited time period (other than the natural fluctuations inherent of short-term figures).

In the days since the Times article appeared, I have been treated to a large volume of e-mails from folks offering various suggestions concerning the cause—everything from the impact of a meeting some five years ago of a large group of transcendental meditators who used their special skills to bring about peace to an increased attachment to community as the recession prevented countless Americans from moving residences.

More than a few of the e-mailers, however, were riders on the abortion-crime link bandwagon, first articulated a decade ago by economists John Donohue and Steven Levitt, who argue that following the 1973 decision in Roe v. Wade, thousands of unwanted fetuses were aborted instead of being born into less-than-ideal environments, thereby producing two decades later a reduction in the pool of at-risk, violence-prone individuals.

Despite persuasive logic, the significance of this effect appears to have been grossly overstated. For example, nearly 60% of the decline in murder since 1990 involved perpetrators ages 25 and older—individuals who would have been born prior to the landmark abortion decision. The abortion-crime link also cannot account for the transient surge in youth homicide during the late 1980s, without which the decline of the 1990s would not have been so dramatic. And, as with all major theories, the abortion-crime hypothesis cannot explain the large drop in murder and other violent crime from the first six months of 2009 to the corresponding months of 2010.

The latest crime figures from the FBI are preliminary, as labeled. More time and data will hopefully help us all to move beyond mere conjecture toward a firmer understanding of the reasons for recent crime trends as well as to determine their permanence. The lower that crime rates plunge, and the more that budgets are cut for crime prevention and crime control initiatives, the greater the likelihood that crime rates will rebound. At some point, unfortunately, we may look back and see these as the good old days.

COMMENTS: 41

I would think that part of the solution could be technological. In the past few years smart phones and mobile internet have begun to penetrate low income groups that are inclined towards committing crime. Perhaps they simply have less opportunity to commit crime because they just have better things to do with their time.

I find it interesting that technology is unmentioned. Just about everyone in the US carries a camera on them that can take a picture and send it anywhere in a moment’s notice. Surveillance systems have become incredibly cheap and convenient. Might this deter someone from, say, snooping around a neighborhood?

Conversely, could technology in the form of social networks and mobile communication be having a socializing/civilizing effect on some troubled people? One trend that fascinates me is seeing people in low-wage jobs happily enraptured in their cell-phones while they’re on their break. These networks have their downsides, but they do seem like a very effective escape from boredom and alienation. The explosion of these networks also coincides with the drops in crime you mention.

Have you seen John Lott’s “More Guns, Less Crime”? What do you think of his stats?

While I am not a professional, I have taken graduate level statistics. I thought Lott’s work pretty sound, but my level of competence is not high enough to make me confident. Thus, I am intrigued by your statement that most gun laws don’t affect crime. You are one of the few to address the issue who do not appear to be massively biased.

There’s been a massive increase in the number of concealed handgun license holders over the past ten years, and what we can say for sure is that the anti-gun argument that “more guns will lead to more crime” has been disproved. That doesn’t mean that more guns will lead to less crime, of course, but the absolute refusal of most economists (et al.) to even contemplate the thought that guns figure into this somehow is pretty disheartening, especially in light of that fact that guns are the ONLY thing such people consider when they compare the amount of gun crime in the US and Europe (and if you look at the [number of guns/gun availability]-to-[gun crime] ratio, the US actually has far less gun crime than Europe.

I don’t think the reality of self-defense matches the romanticized view. Criminals don’t tend to be the brightest bulbs in the box. Anyone that would actually stop to consider the ramifications of their actions isn’t likely to go out and commit violent crimes in the first place. A lot of these people see jail and death as inevitable and if they remain willing to violently confront armed members of rival gangs, accosting citizens would be almost a no brainier in comparison. Anyway if more guns did result in a deterrent effect there would have probably been a learning curve associated with it where self-defense shootings would increase thus causing a response from violent criminals to commit less crime. I am currently unaware of any such increase.

Second simply committing less crime isn’t a criminal’s only option. Many crimes are not committed without the intent to cause harm. A robber just wants the money, not to get into a fight. If a robber stands a real risk of encountering an armed citizen then his best counter-strategy is to immediately resort to violence to incapacitate the victim so that they cannot defend themselves. Therefore any change in crime that relied solely on self-defense deterrence would be highly susceptible to this sort of backlash. Again this could be tracked by seeing a spike in self defense shootings followed by an increase in aggressive attacks against victims.

The name of Lott’s book is actually a bit wrong. According to Lott’s stats, what decreases is violent crimes. Nonviolent property crimes actually increase according to his stats. People stop robbing and start thieving. For example, car jacking go down, but old fashioned car thefts go up.

I don’t know about romanticism, but self defense does stop crimes. You need only remember the plane that crashed in Pennsylvania, the shoe bomber, and the congress woman in Arizona to know it does happen. The question is whether, in the aggregate, guns make enough of a difference one way or another to suggest a policy.

Mike B.’s logic is flawed: “A robber just wants the money, not to get into a fight. If a robber stands a real risk of encountering an armed citizen then his best counter-strategy is to immediately resort to violence to incapacitate the victim so that they cannot defend themselves.”

If a robber just wants money/property at the least cost, which is to avoid conflict, then the robber will not choose a victim the robber beleives will cause a confrontation. The robber’s best strategy would be to avoid the person the robber beleives may be able to defend themselves and choose an easier victim who will capitulate. This is why self defense and concealed carry work – deterrence.

I wonder if there is enough data to study the effect of video games, cable TV and the million and one distractions provided by the internet are having on crime. As Mike B points out, people with more distractions would, logically, have less opportunity to commit crime (it’s difficult to go mug someone in the middle of a game of Halo).

I remember the uproar over midnight basketball during the Clinton administration and the argument that this would keep restless youth off the streets. Maybe all the new technology of the past 15 years has had the same effect. It would be interesting to the see the results of a scientific analysis of this possibility.

I think that is a really interesting concept. Perhaps, studies may already exist demonstrating TV’s effect on crime. TV has been around for alot longer then our new age technology and we have real data concerning its usage in America, which spans decades. Can you find any studies that may shed some light?

That, and the reality of human nature is that people bend before they break. A lot of people are making plenty of sacrifices, but it isn’t quite to the point where you *have* to take your neighbor’s meal in order not to starve yourself.

What is more interesting is the increasing division between the wealthy and the poor. As history has shown, the economies on that only work out for so long before legitimate revolution happens. Many countries already seem to be at that breaking point. When it gets that bad, though, does it still get classified as “crime”?

Funny, but your link doesn’t actually support your position. It contains, at best, a *claim* that the position has been rejected, yet even the link it goes to on Wikipedia doesn’t directly support that claim. If you have better references, please post them instead.

That said, the very idea that the people revolt when things are “better” strikes me very much like the notion that the elite think they might be able to appease the masses by throwing them a bone. Unfortunately, I don’t think people are receptive to that after they’ve reached the breaking point.

Again, I would love to see a really meaty reference that supports your point, because it sounds outlandish on the face of it. While being poor might not be enough as the *only* reason to revolt, the inequity it represents is almost certainly in the mix with all the other class-based divisions that are factors in a revolution.

almost no one considered the fact that more than half of the states either decriminalized marijuana or drastically changed their total drug policy in a trending shift towards legalization. Most “crimes” are drug related.

The risk/reward ratio of teens and young adults stealing and causing mayhem in the real world is much worse than the risk/reward ratio of doing it in a video game. Without these kids out on the street committing petty crimes out of boredom, they then never graduate to more serious ones.